KeywordTool.io - KeywordTool.io is the best FREE alternative to Google Keyword Planner and Ubersuggest. It uses Google's autocomplete feature to get over 750+ long-tail keywords for any given query.
Keyword Discovery - Keyword Discovery is a keyword research and analysis tool.
Google Trends - Explore Google trending search topics with Google Trends.
Keyword Country - Keyword Country is an AI-powered keyword research tool.
Keywords Everywhere - Free browser add-on for keyword volume, CPC & competition
GrepWords - Grepwords is an API-first Google Keyword Suggestion Tool.